There are various lighting devices designed for satisfying different needs. For example, there are light bulbs to be installed on sockets. Such light bulbs are usually easy to be installed by users. For downlight devices used in normal home, it would be important to consider convenience for installation, safety and replacement.
Among light devices, downlight devices are popular. Various downlight devices may be in lots of places around the world. Usually, there is a cavity or an installation box in a ceiling. A downlight device is installed in the cavity or the installation box. Wires are connected to an external power source, like a 110V or 220V alternating current.
Sometimes, a control signal is also provided to the downlight device to control a luminance level of the downlight device.